The present invention relates to a device for freezing biological products stored in tubes, ampoules, phials or straws of the kind comprising a thermally insulated casing of elongated shape between a supporting base arranged to receive liquid nitrogen and a cover incorporating means of supporting the said tubes, ampoules or phials, and means for engendering a circulation of gas.
In a device of this nature, the cooling speeds are obtained in automatic manner either by controlling an electromagnetic valve placed in the liquid nitrogen supply circuit, or by controlling a heating resistance situated in the gas circuit, and the operation is conducted in accordance with a program arranged in such manner that the biological products are cooled progressively to a freezing temperature, the cooling operation continuing in gradual manner as far as the temperature required, after which said products are immersed in liquid nitrogen for preservation.
It is an object of the invention to provide a device for freezing biological products of the kind hereinabove referred to, which allows progressive cooling of biological products stored in plastic tubes, glass ampoules, phials or straws to be secured by freezing means which are uncomplicated in operation, compact, semi-automatic, inexpensive, rendering it possible to obtain predetermined and reproducible temperature decreases, to ensure an optimum rate of cell survival after freezing and storage in a bath of liquid nitrogen.